I recently had a sharpening customer with the exact same problem you were stating but on a CPM-154 knife. He was having trouble getting it sharp, and said it wouldn't even hold an edge. I suspected it just needed to be sharpened properly, but he said he even sent it to a professional for a second opinion.
Well, I received the knife, and it had a 25 degree microbevel... aka, it had no bite and didn't feel that sharp to the touch either. I simply sharpened it at 15 degrees with no microbevel. He reported back that the knife was doing much better. I do not microbevel knives unless the steel sucks. I would not recommend microbeveling my knife as the steel is tough enough not to need it.
Here's part of the actual email:
"I've had it for close to a year. In that time, I have never been able to keep it sharp. I can briefly get it sharp....but it is *minutes* of use before tomatoes are just kicking its butt. For reference, I have the Goko I just got from you, a 10" Shun Elite Gyoto and several Nenox G series blades that simply run circles around the Addict...and keep their edges. A long time. (BTW....the Goko is COMPLETELY FANTASTIC.).
The straw that broke the camels back:
I took the Addict into ******* Cutlery last week and had it professionally sharpened to see if maybe I was just being stupid. The initial cuts after the sharpening were pretty good....not Goko or Shun good...but OK....but within 10 minutes of use...once again....things went badly. The ******* Cutlery guys commented they thought there could be a tempering issue with the blade. I have no idea....maybe you will if you play with it."
................Now, I got the knife after the ******* Cutlery guys got it, and the edge was certainly nothing to write home about, to be nice. Albeit even, the edge was well over 20 degrees after I inspected it. No bite whatsoever. So, here's the rest of the emails later and his response.
"Send it to my buddy Shaun for sharpening. He does them cheaply and if you include a note about testing it I'm sure he would be happy to test drive it to make sure it's good.
If it won't hold it's edge we can discuss.
No problem, I've sharpened a bunch of those and will happy to have a look at it for you. Please ship to: ***
(Yes, I did his knife for free because that's how we roll at CKTG)
Knife is finished. She is sharp at 15 degrees, no microbevel. It will have that bite you are looking for, and will hold it much better. This steel is not easy to sharpen, there are many tough things about it, but it will take a great edge and I do really like it. Just not for an inexperienced sharpener, that's all. If you are having any trouble beyond this point then it would have to be heat treat. The heat treat on Richmond knives is almost second to none, and I really haven't seen a lemon in that respect in the couple of years I've been doing them.
Knife will ship tomorrow morning, please let me know how you like it, I want your feedback on the steel. Thanks again John.
..............and his response:
"Some weirdness here. I just now realized I did NOT send an email to you that was essentially bad news on the sharpening right after I got the knife back. It's all typed up and sitting in my Drafts folder. The good news is that that email was wrong. I 'powered through' my initial disappointment and have been using the Addict regularly...and it's great. You did a fantastic job. That steeper angle is everything. I've hit it very lightly with a ceramic steel....but nothing else. It's holding its edge very well.
So thank you and I feel bad that I have left you in the dark for several weeks. Even though my initial response to you was not the greatest.
.................I've tried to contact him back and thank him for the feedback but I keep getting failure notices. Looks like I finally got one through tonight though. haha
Anyhow, I hope this helps anyone else who reads it and may be having trouble getting that "perceived" sharpness they are looking for. Just sharpen a little steeper, and remember that honing goes a long way in keeping that bite. S35vn does quite well on ceramic I find.